INTRODUCTION: Epileptic men may experience hormonal changes that may alter semen quality and sexual function. Alterations in male sexual and reproductive parameters may also be due to treatment with antiepileptic drugs to control seizures. AIMS: To evaluate serum hormone concentrations, semen quality, the frequency of sexual intercourse (FSI), and erectile function in men with epileptic seizures controlled by carbamazepine (CBZ). MAIN OUTCOME MEASURES: The five-question form of the International Index of Erectile Function (IIEF-5), and semi-structured questionnaire. METHODS: One hundred and eighteen men, aged 18-45 years, were included in this controlled, cross-sectional study: 63 men taking CBZ (epileptic group) were compared to 55 healthy men (control group). Blood sample was collected to determine hormones concentrations. Erectile function and the frequency of sexual relations were assessed by using questionnaires. Sperm morphology was analyzed by examining the quality of the head, intermediate part and tail of the spermatozoa. RESULTS: Using the IIEF-5, we observed a significant association between erectile dysfunction (ED) and groups (P < 0.01), where epileptic men had 17.33 (95% CI 3.59, 83.52) odds to have erectile dysfunction. Adjusted odds ratio to group considering luteinizing hormone, prolactin, Serum total testosterone, androstenedione, and dehydroepiandrosterone, androstenedione levels and free androgen index, we observed only group effect where epileptic men had 10.47 (95% CI 2.75, 39.83) odds to have FSI < 3 times a week. Sperm vitality was altered in 27% of the epileptic subjects compared with 5.4% of the control group (P < 0.002). Sperm motility differed significantly between groups, with A + B motility ≤50% observed in 98.4% of the epileptic group and in 85.4% of the control group (P < 0.01). Sperm morphology <14% was observed in 93.7% of the epileptic men, compared with 34.6% of the controls (P < 0.001). CBZ users, showed less sexual intercourse then controls (P ≤ 0.001). CONCLUSIONS: Epileptic men taking CBZ present with changes in hormonal levels, altered semen quality, ED, and a reduction in coital frequency.